This invention relates to a sealing composition for various substrates, including floors or metallic surfaces. In particular, it relates to an improved self-polishing sealer for floors, which provides better adhesion for later-applied water-based floor finishes.
Sealing compositions have been widely utilized and are normally applied over substrates to prepare them for final finishes. Commercially available sealers for floors, metal parts and other substrates have several major limitations. For example, resilient floors, which have not been thoroughly cleaned or which have been maintained with buffable waxes, tend to build up hydrophobic residues of oily or waxy hydrocarbons. Further, a protective hydrophobic or mill finish coating is often applied to new flooring. Flooring, which has been maintained or prepared to contain a hydrophobic coating or residue, resists application of water-based waxes, sealers or protective coating, due to a lack of adhesive sites.
Metal parts are often coated with waxy or oily release agents to expedite processing in mold-forming machines. A rust retardant must be able to penetrate the release agent to adhere to and seal the part. Machine parts having a lubricating layer require a protective paint finish, periodically. Conventional water-based paints do not adhere to oily lubricated surfaces. Tile floors contain minute pores which have a tendency to collect waxes and other residues. These waxes and residues form a seal on the tile and prevent the tile beneath from being wetted by water-based finishes.
In each of the problem areas illustrated above, a sealing composition is required which can penetrate the oily or waxy residues to provide anchoring or adhesion sites for a water-based finish, such as a floor polish, paint, wax or protective coat.
Previously, substrates with accumulated hydrophobic residues were treated with hydrocarbon-solvent-based sealers. However, such organic solvent-based sealers have been criticized as environmentally undesirable, as unduly expensive and wasteful of petroleum feedstocks and as detrimental to work-place safety. Such organic solvent based sealers are not self-polishing and require buffing. Water-based coating compositions are preferred, since they meet previous objections and can be formulated to be self-polishing. Unfortunately, prior, water-based compositions do not provide sufficient adhesion to substrates previously treated with oil-based buffable finishes.
It is most desirable for many applications that the sealing composition dry to a glossy film (dry-bright) without the need for time-consuming and expensive buffing steps. It has, therefore, long been desired to provide a self-polishing sealing composition for substrates having pores filled with hydrophobic residues, which will provide enhanced adhesive sites for a later applied water-based finish.
In columns 7 and 8 of U.S. Pat. No. 2,862,899 there is disclosed an emulsion polish optionally employing a hydrocarbon solvent. The solvent functions to disperse or dissolve the active wax and polytrifluorochloroethylene ingredients. The polish does not dry bright and normally requires buffing to achieve a glossy finish. Minor amounts of resin, below 10% by weight, are optionally employed as a diluent for the wax.
A water-based coating composition containing a hydrocarbon is disclosed, in U.S. Pat. No. 3,086,871, as useful for plugging pores in chrome plate. The composition must be buffed to provide gloss and does not contain film-forming polymers. U.S. Pat. No. 2,993,800 describes compositions useful as sizings for paper, which employ solvents to dissolve wax for ease in handling. U.S. Pat. No. 3,393,078 discloses a water based emulsion polish containing a volatile hydrocarbon and a wax. This composition does not dry bright, but is buffed after application. No film-forming polymeric coating agents are present.